Sunday's move by the Canadian Food Inspection Agency (CFIA) follows the quarantine of nine farms in Oxford County last week after an outbreak of H5N2 avian influenza was detected at a commercial turkey operation west of Woodstock, where 44,000 birds died or were destroyed.

An official said Sunday the move doesn't mean there's an increased risk or food-safety threat, however.

Instead, the control zone -- extending out 10 km from the farm where the virus was found, double last week's containment perimeter -- is being created to protect the poultry trade, an industry worth hundreds of millions of dollars a year to Ontario and looms large in the province's southwest.

"The establishment of the zone is to define clear boundaries to allow for resumption of trade from areas outside the zone," said Abed Harchaoui, the CFIA's senior veterinarian.

Canada's largest trading partner, the U.S., has barred poultry products from within the avian flu control zone in Oxford County.

So far, 15 countries have blocked the import of Canadian or Ontario poultry products. Many of those restrictions are from an avian blu outbreak in British Columbia late last year.

Five additional countries have joined the list since the case west of Woodstock was confirmed last week.

"The only additional market that imposed a restriction in the last 24 hours is Barbados, for live and poultry products specific to Ontario," said Marco Valicenti of Agriculture and Agri-Food Canada.

Industry spokespeople were not immediately available for comment.

But while the control zone may allow some Canadian poultry farms to breath a sigh of relief, it will be a challenge for affected producers: All movements are heavily restricted on quarantined farms.

Any birds, machinery, feed or waste materials going in and out of a quarantined operation will have to be authorized by the CFIA, Harchaoui said.

"There would be a significant impact on farms that are going under quarantine," Shayan Sharif, an expert in avian flu and pathobiology at the Ontario Veterinary College, has said. "They have to be able to disinfect some of the equipment that the CFIA investigators identify for the poultry farmers," he told QMI Agency in the fallout of the Oxford case.

None of the farms under quarantine has shown signs of avian flu, aside from the originally infected property, Harchaoui said.

But the control zone will not be removed until the infected farm is completely free of avian flu.